The present invention relates generally to electronically scanned antennas, and more particularly, to an electronically scanned semiconductor antenna.
Conventional, electronically scanned arrays and phased arrays are realized in two geometries, including a passive electronically scanned array using ferrite phase shifters, and an active electronically scanned array using transceiver modules. At millimeter-wave frequencies, the center-to-center antenna element spacing ranges from 0.200 inches at Ka-band to 0.060 inches at W-band. Within a square cross-section of this dimension, an active transceiver module or a reciprocal phase shifter assembly must be mounted and control lines must be made accessible.
In order to illustrate the magnitude of this antenna design problem, consider as an example a 25.times.25, fully populated Ka-band active electronically scanned array. Also assume five power and signal control lines are needed per antenna element. This means that 625 modules must be packaged with 3,125 power and control lines, a 625 way RF power divider network and sufficient heat sinking to dissipate the heat from the modules. The present invention will reduce considerably the amount of hardware necessary for a millimeter-wave phased array.
Conventional, electronically scanned, phased arrays are not yet practical for millimeter-wave applications. The center-to-center element spacing, 0.060 inches at W-band (94 GHz) and 0.100 inches at V-band (60 GHz) and 0.200 inches at Ka-band (35 GHz), is not conducive to the packaging of such arrays. Passive ferrite phase shifters above Ka-band (35 GHz) have only recently become available and are generally lossy, current controlled devices and active transceiver modules are in their infancy of development. W-band transmit/receive module electronically scanned array antennas are not feasible with conventional technology.
Accordingly, it is an objective of the present invention to provide for an electronically scanned semiconductor antenna.